Boulder Supply Canal

Boulder Supply Canal

Established: 1955

Once called the Boulder Feeder Canal, the Boulder Supply Canal transports water from the Big Thompson/Windy Gap Project into Boulder Reservoir. The water begins its journey as the headwaters of the Colorado River before it is first stored in a series of interconnected high mountain lakes: Grand Lake (Colorado's largest natural lake), Shadow Mountain Lake, and Lake Granby (Colorado's second-largest reservoir). From there, the water travels underneath Rocky Mountain National Park and the Continental Divide through the Alva B. Adams tunnel, into a series of reservoirs and canals, before finally spilling into Boulder Reservoir.